STOCKHOLDERS’ EQUITY

Authorized Stock

In June 2018, our stockholders approved an amendment and restatement of our Certificate of Incorporation to reflect an increase in the number of authorized shares of our common stock from 175 million shares to 300 million shares. In addition to the increase in the authorized number of shares of common stock, the amendment eliminates designated series of preferred stock that are obsolete and are no longer outstanding or issuable, including Series B Junior Participating Preferred Stock and Series E Convertible Voting Preferred Stock. As of December 31, 2018, we had five million shares of preferred stock authorized. The amendment was filed with the Delaware Secretary of State in June 2018.

Stockholder Rights Agreement

On November 29, 2010, our Board of Directors approved a stockholder rights agreement (the "Stockholder Rights Agreement"), effective December 13, 2010. A stockholder rights agreement is designed to deter coercive, unfair, or inadequate takeovers and other abusive tactics that might be used in an attempt to gain control of our company. A stockholder rights agreement will not prevent takeovers at a full and fair price, but rather is designed to deter coercive takeover tactics and to encourage anyone attempting to acquire our company to first negotiate with our Board of Directors.

On March 27, 2018, we entered into a Second Amendment to Rights Agreement which had the effect of suspending the Stockholders Rights Agreement as of March 30, 2018, though it will expire under its terms on December 13, 2020.

Common Stock Issuable

As of December 31, 2018, 5.0 million shares of our common stock were issuable upon the exercise of granted stock options (regardless of whether in or out-of-the-money).

Warrant Activity

We typically issue warrants to purchase shares of our common stock to investors as part of a financing transaction or in connection with services rendered by placement agents or consultants. During 2018, our previously outstanding warrants were exercised, and therefore no outstanding warrants remained as of December 31, 2018. A summary of warrant activity is as follows:



	Number of Shares		Weighted Average Exercise Price
Outstanding — December 31, 2016	445,000		$	6.78
Granted	—		—
Outstanding — December 31, 2017	445,000		$	6.78
Granted	—		—
Exercised	(445,000	)	$	6.78
Outstanding — December 31, 2018	—		—
Exercisable — December 31, 2018	—		$	—

Sale of Common Stock Under ATM Agreements

In December 2015, and August 2017, we entered into a collective at-market-issuance sales agreement with FBR Capital Markets & Co., MLV & Co. LLC, and H.C. Wainwright & Co., LLC. (“December 2015 ATM Agreement” and the "August 2017 ATM Agreement", respectively). These agreements allowed us to raise aggregate gross proceeds through these brokers of up to $250 million from the sale of our common stock on the public market.

Through December 31, 2018, we had raised gross net proceeds of $202.1 million through these at-market sales, of which

$128.3 million was raised during the year ended December 31, 2017. We are using these proceeds to continue to develop our product pipeline and to provide additional capital structure flexibility.

We sold and issued shares of our common stock under both the December 2015 and August 2017 ATM Agreements, summarized as follows:



	No. of Common Shares Issued	Proceeds Received (Net of Broker Commissions and Fees )
Common shares issued pursuant to the December 2015 ATM Agreement during the year ended December 31, 2016	10,890,915	$	73,869
Common shares issued pursuant to the December 2015 ATM Agreement between July 1, 2017 and July 31, 2017	3,243,882	$	23,745
Common shares issued pursuant to the August 2017 ATM Agreement between August 1, 2017 and December 31, 2017	10,314,250	$	104,527

There were no sales of our common stock under the August 2017 ATM Agreement during the year ended December 31, 2018.